The long-term goal of the project is the identification of genes that contribute to the overall genetic risk in bipolar disorder and the characterization of the biological function of these genes. It is anticipated that improvements in treatment, diagnosis and possibly prevention will evolve once genetic contributions to affective disorders are established. At present, the NIMH-IRP site is functioning primarily to collect additional affected bipolar sib pairs to enlarge the overall sample available to the NIMH grant-funded Bipolar Genetics consortium. In the past year, the NIMH-IRP site enrolled 27 BP families and completed interviews and submitted blood samples on 25 affected sibling pairs plus 51 family members. Other families are in varying stages of completing the protocol requirements. The completion of the first genome scan on multiplex families with bipolar affective disorder by our consortium provided evidence for susceptibility regions on 13q32, 1q32 and 18p11.2. Additional findings were published recently. Interestingly, some of these regions overlap with proposed chromosomal areas containing predisposing loci for schizophrenia. These results raise the possibility that schizophrenia and affective disorders share some susceptibility loci. Identifying candidate gene (genes localized in susceptibility regions) will require use of developing genetic technologies.